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Titolo:
Proton NMR relaxation studies of solid tyrosine derivatives and their mixtures with L-leucinamide
Autore:
Wang, YL; Belton, PS; Tang, HR;
Indirizzi:
AFRC, Inst Food Res, Norwich Lab, Norwich NR4 7UA, Norfolk, England AFRC Norwich Norfolk England NR4 7UA b, Norwich NR4 7UA, Norfolk, England
Titolo Testata:
SOLID STATE NUCLEAR MAGNETIC RESONANCE
fascicolo: 1, volume: 14, anno: 1999,
pagine: 19 - 32
SICI:
0926-2040(199906)14:1<19:PNRSOS>2.0.ZU;2-B
Fonte:
ISI
Lingua:
ENG
Soggetto:
ENZYMATIC CATALYSIS; MOLECULAR MOTIONS;
Keywords:
NMR relaxation; tyrosine derivatives; benzene ring motion;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
--discip_EC--
Citazioni:
24
Recensione:
Indirizzi per estratti:
Indirizzo: Belton, PS AFRC, Inst Food Res, Norwich Lab, Colney Lane, Norwich NR4 7UA,Norfolk, England AFRC Colney Lane Norwich Norfolk England NR4 7UA rfolk, England
Citazione:
Y.L. Wang et al., "Proton NMR relaxation studies of solid tyrosine derivatives and their mixtures with L-leucinamide", SOL ST NUCL, 14(1), 1999, pp. 19-32

Abstract

Proton NMR relaxation time measurements were carried out on solid tyrosinederivatives: acetyl-L-tyrosine ethyl ester (Ac-Tyroet), N-carbobenzyloxy-L-tyrosine ethyl ester(CBZ-Tyroet), N-trifluoroacetyl-L-tyrosine ethyl ester(TFAc-Tyroet) and their mixtures with L-leucinamide, It was found that spin-lattice relaxation was driven mainly by methyl group rotation at low temperature for the pure solids and the mixtures. Benzene ring flipping motion and a third motion (possibly whole molecule tumbling) were found to be responsible for relaxing Ac-Tyroet and CBZ-Tyroet at high temperature. However,these motions were highly hindered in TFAc-Tyroet. Molecular tumbling motion was detected in the supercooled liquid mixtures of L-leuNH/CBZ-Tyroet and L-leuNH/Ac-Tyroet, while this motion is absent in the mixture L-leuNH/TFAcTyroet. The hindered motion in TFAc-Tyroet may be one of the factors affecting its ability to form a supercooled liquid with L-leucinamide. (C) 1999 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 24/09/20 alle ore 10:11:41